System for tire inflation

ABSTRACT

A system for tire inflation including a drive mechanism defining a rotational axis, including an eccentric mass that offsets a center of mass of the drive mechanism from the rotational axis along a radial vector; a pump arranged radially distal the rotational axis of the drive mechanism, including a chamber defining a chamber lumen, and a reciprocating element arranged at least partially within the chamber lumen and translatable along a pump axis; a drive coupler coupled between the drive mechanism at a first position and the reciprocating element at a second position fixed to the reciprocating element; a torque regulation mechanism; and a controller, communicatively coupled to the torque regulation mechanism; wherein the system is operable between at least a first mode and a second mode by the torque regulation mechanism in cooperation with the controller.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 16/276,998 filed 15 Feb. 2019, which is a divisional of U.S.patent application Ser. No. 15/696,816 filed 6 Sep. 2017 which claimsthe benefit of U.S. Provisional Application Ser. No. 62/383,910, filed 6Sep. 2016, and U.S. Provisional Application Ser. No. 62/519,061, filed13 Jun. 2017, each of which is incorporated herein in its entirety bythis reference.

This application is a continuation-in-part of U.S. patent applicationSer. No. 16/161,771 filed 16 Oct. 2018, which is a continuation of U.S.application Ser. No. 15/280,737 filed 29 Sep. 2016, which claims thebenefit of U.S. Provisional Application No. 62/235,121 filed 30 Sep.2015 and is a continuation-in-part of U.S. application Ser. No.14/839,009 filed 28 Aug. 2015, which is a continuation of U.S.application Ser. No. 14/198,967 filed 6 Mar. 2014, which is acontinuation of U.S. application Ser. No. 14/019,941 filed 6 Sep. 2013,which is a continuation of U.S. application Ser. No. 13/797,826 filed 12Mar. 2013, all of which are incorporated in their entireties by thisreference.

TECHNICAL FIELD

This invention relates generally to the pumping field, and morespecifically to a new and useful tire-mounted pumping system in thepumping field.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic representation of the tire inflation system.

FIG. 2 is a schematic representation of a variation of the tireinflation system.

FIGS. 3A-3C are schematic representations of example configurations ofthe tire inflation system.

FIGS. 4A-4B are top views of example relative configurations of thedrive mechanism and the torque regulation mechanism.

FIG. 5 is a schematic of an example configuration of a slotted camconfiguration of the drive coupler of the tire inflation system.

FIG. 6 is an exploded view of a variation of the tire inflation system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the inventionis not intended to limit the invention to these preferred embodiments,but rather to enable any person skilled in the art to make and use thisinvention.

1. Overview

As shown in FIG. 1, the system for tire inflation 100 includes a drivemechanism 120, a primary pump 130, a drive coupler 140, and a torqueregulation mechanism 150. The system can optionally include an energystorage device 160, one or more sensors 170, and a controller 180. In avariation, the drive mechanism 120 includes a cam 122 and an eccentricmass 121, the primary pump 130 includes a reciprocating element 131 anda pump body 132, and the torque regulation mechanism 150 includes afirst portion 151 (e.g., a stator) and a second portion 152 (e.g., arotor).

The system functions to inflate a tire. The system can also function totranslate rotational motion into reciprocating linear motion that can beused to drive a tire inflator (e.g., a pump). The system can alsofunction to translate relative motion between the primary pump 130 andcam 122 into a pumping force, wherein the eccentric mass 121 retains thecam 122 position relative to a gravity vector while the primary pump 130rotates relative to the cam 122. The system can be operable betweenseveral modes, including a pumping (e.g., active) mode and afreewheeling (e.g., passive) mode. In the pumping mode, the tireinflation system 100 preferably pumps an external fluid, such as air,into the tire interior. The external fluid is preferably received from afirst reservoir 910 (e.g., the external environment, a canister, etc.)during a recovery stroke of the primary pump 130 and pumped into asecond reservoir (e.g., the tire) during a compression stroke of theprimary pump 130. However, the fluid can be otherwise suitably pumped.The first reservoir 910 is preferably the ambient atmosphere at a firstpressure, and the second reservoir is preferably the tire interior(e.g., bladder) at a second pressure higher than the first pressure.However, the first and second reservoirs can be any other suitable fluidreservoirs at any other suitable absolute and/or relative pressures. Infurther alternatives, the fluid can be a fluid other than air (e.g.,liquid water, pure nitrogen, etc.).

In a first variation of the freewheeling mode, the eccentric mass 121 ofthe drive mechanism 120 rotates at substantially the same velocity asthe wheel (and, thus, as the primary pump 130) such that a negligible(e.g., zero, substantially zero) drive force is supplied by the drivemechanism 120 to the primary pump 130. In the first variation, thetorque regulation mechanism 150 can supply a torque to the eccentricmass 121 to excite the mass into rotation about a rotation axis (e.g.,of the wheel hub) at the same velocity (e.g., substantially the same,exactly the same) as the wheel, whereupon angular momentum of theeccentric mass 121 substantially maintains the eccentric mass 121 inrotation. Upon excitation of the eccentric mass 121 into rotation at thesame velocity as the wheel, the torque regulation mechanism 150 cancease supplying the torque. However, in an alternative implementation ofthe first variation of the freewheeling mode, the torque regulationmechanism 150 can supply a torque (e.g., continuously, periodically,asynchronously, etc.) to maintain the eccentric mass 121 in rotationabout the rotation axis at a suitable velocity such that a negligibledrive force is supplied by the drive mechanism 120 to the primary pump130.

In a second variation of the freewheeling mode, the eccentric mass 121can be statically connected to the system housing no and/or wheel. Inthe second variation of the freewheeling mode, the eccentric mass 121rotates along with the housing 110 at the wheel speed, acted upon by amechanical force supplied by the static connection. For example, theeccentric mass 121 can be clipped, latched, buckled, snapped, orotherwise suitably fastened to the housing 110 and/or any portion of thesystem or system-related component rotating along with the wheel (e.g.,in a reference frame rotating at the same angular velocity as thewheel). However, the eccentric mass 121 can be otherwise suitablystatically connected to the system housing 110 and/or wheel in thesecond variation of the freewheeling mode.

In a third variation of the freewheeling mode, the eccentric mass 121can be rotationally decoupled from (e.g., rotates freely relative to)the system housing 110 and/or wheel. In the third variation of thefreewheeling mode, rotation of the eccentric mass 121 (e.g., whenrotationally decoupled) does not supply a drive force to the primarypump 130 via the cam 122 and drive coupler 140. For example, the systemcan include a clutch that can engage and disengage the eccentric mass121 from the cam 122, wherein the eccentric mass 121 and the cam 122 aredisengaged during system operation in the freewheeling mode, and engagedin the pumping mode. In another example, the system can include a clutchthat can engage and disengage the cam 122 from the drive coupler 140,wherein the cam 122 and the drive coupler 140 are disengaged duringsystem operation in the freewheeling mode, and engaged in the pumpingmode. However, in the third variation of the freewheeling mode, thesystem can additionally or alternatively include any suitable mechanismfor rotationally decoupling the drive mechanism 120 from the primarypump 130.

In a fourth variation of the freewheeling mode, the eccentric mass 121is maintained at a hanging angle of substantially zero degrees relativeto a gravity vector, such that no reciprocating action is produced bythe cam 122 upon the reciprocating element 131 of the primary pump 130.In the fourth variation, the eccentric mass 121 is preferably maintainedat a zero hanging angle by the torque regulation mechanism 150, but canadditionally or alternatively be otherwise suitably maintained at a zerohanging angle (e.g., by a locking mechanism).

The system is preferably operable between the pumping and freewheelingmodes by the torque regulation mechanism 150 in cooperation with thecontroller 180. Controller 180 operation can include generating controlinstructions based on any suitable control algorithm, and incorporatingany suitable sensor inputs. The control instructions can be generated inreal-time, near-real time, or at any suitable time. The controlinstructions and/or parameter values thereof can be selected (e.g., froma database) based on the sensor input values or patterns (e.g.,eccentric mass angular kinematics, system lateral kinematics, vehiclekinematics, etc.), calculated (e.g., target operation values calculatedbased on the sensor input values), optimized (e.g., for pumping, energyharvesting, eccentric mass rotational frequency, etc.), or otherwisedetermined. However, the system can be otherwise suitably operablebetween any suitable operating modes by any suitable control and/orregulation mechanism.

The tire inflation system 100 preferably discontinuously inflates thetire (e.g. via periodic inflation, wheel speed-controlled inflation,actively controlled inflation, pressure-dependent inflation, etc.), butmay continuously inflate the tire. The tire inflation system 100 ispreferably powered by a direct mechanical linkage to the rotating wheel,such that the inflation system pumps fluid into the tire when the tirerotates; but the tire inflation system 100 can alternatively be poweredby an actuator that is decoupled from the rotation of the tire (e.g., anelectric motor having a separate power source). The tire inflationsystem 100 can pump fluid using a diaphragm system, a peristalticsystem, a piston system, or any other suitable pumping mechanism. Thetire inflation system 100 preferably mounts to a wheel (e.g. to the hubof a wheel), and preferably connects to the tire interior through avalve of the tire. The tire inflation system 100 is preferablyconfigured to be mounted to the wheel for an extended period of time(e.g., on the order of weeks, months, or years); accordingly, removal ofthe tire inflation system 100 for routine tire pressure checks can beomitted.

2. Benefits

Variants of the systems and/or methods can confer several benefitsand/or advantages. First, variants of the system can provide improvedresistance to entering an undesired spin condition in which theeccentric mass 121 rotates at substantially the same angular velocity asthe wheel (e.g., the freewheeling mode) when reciprocal pumping isdesired, by providing torque input to the eccentric mass 121 via thetorque regulation mechanism 150. The torque input can be modulated toprovide a counter-force to torque ripple caused by the reciprocatingpump (e.g., a back torque acting upon the eccentric mass 121), toprovide a counter-force to large back torques produced by the primarypump 130 during the compression stroke when the system is operated atlow vehicle speeds and/or starting from a stopped state (e.g., zerovelocity), and/or to provide a counter-force to transient forcesresulting from road and/or driving irregularities (e.g., bumps,undulations, vehicle acceleration and deceleration, etc.). This can, inturn, actively increase the amount of time during driving in which thesystem can usefully pump air using energy harvested from the eccentricmass 121.

Second variants of the system can enable the tire inflation system 100to be controllable (e.g., actively controllable) between the pumping andfreewheeling modes, by transitioning the pendulum (e.g., eccentric mass121) into the freewheeling mode (e.g., wherein the pendulum is rotatingat the wheel rotation speed) during periods in which the tire does notrequire inflation. By operating in the freewheeling mode during periodsin which the tire(s) do not require inflation, wear on system components(e.g., reciprocating pump components) can be reduced and themaintenance-free system lifetime can be thus increased. The torqueregulation mechanism 150 (e.g., in cooperation with a control system)can also actively transition the system into the pumping mode, byproviding a torque against the eccentric mass 121 to control the hangingangle of the eccentric mass 121 relative to a gravity vector (e.g., tostop the eccentric mass 121 from rotating at the wheel rotation speed).In one variation, this includes: determining the wheel rotation speedand controlling electric motor rotor rotation to substantially match thewheel rotation speed. In a second variation, this includes: determiningthe eccentric mass 121 angle relative to the gravity vector, determininga desired angle, and controlling the electric motor (e.g., the electricmotor rotation speed, the angular position of the electric motor, thecurrent or voltage supplied to the electric motor, etc.) to adjust theeccentric mass 121 angle to substantially match the desired angle.However, the system can be otherwise transitioned into the pumping mode.By transitioning into the pumping mode without relying on a passive exitfrom the freewheeling mode (e.g., due to normal perturbations to therotary motion arising from road surface irregularities and/or drivingbehavior), fluid can be provided to the tires on demand (e.g., whentires require immediate inflation, imminent inflation, etc.).

Third, variants of the system can confer several benefits related toon-demand, real-time tire inflation. Tires that are properly inflatedimprove vehicle fuel economy, and have longer lifetimes beforereplacement becomes necessary. Adjustable tire pressure in real ornear-real time also enables adjustment of tire parameters (e.g.,compressibility) to road and/or environmental conditions. For example,the tire pressure can be increased to take advantage of reduced rollingresistance on recently paved, smooth roads where the risk of a tirerupture due to road roughness is low. In another example, tire pressurecan be automatically adjusted to account for changes in ambient pressureand/or temperature, such that an optimal pressure difference between theinterior and exterior of the vehicle tire(s) is maintained.

Fourth, variants of the system can be distributed at each wheel of thevehicle (or a subset of wheels of the vehicle), which can reduce thecost of an auto-inflation system compared to a centralized inflationsystem and can enable the control of tire pressure on a per-wheel basiswithout the need for complex and expensive plumbing, valve networks,and/or pressurized fluid manifolds. Performing pressurization at thewheel-end can also reduce the likelihood of pressure system failure dueto a reduction in the number of pressurized system components, which canbe vulnerable to shock and vibration damage when routed beneath avehicle.

Fifth, variants of the system can be physically rugged, robust, and/orotherwise resilient to the harsh environment in the vicinity of thewheel due to exposure to road debris and other hazards. The placement ofvariants of the system at the wheel hub area provides a well-suited areafor physically shielding system components between the wheel hub and anouter surface of the system housing 110.

However, the system and/or method can confer any other suitable benefitsand/or advantages.

3. System

As shown in FIG. 2, the tire inflation system 100 can include: a housing110; a drive mechanism 120 that includes a cam 122 and an eccentric mass121; a primary pump 130 that includes a reciprocating element 131, apump body 132, a return mechanism 133, and one or more inlets 134; adrive coupler 140 that connects the drive mechanism 120 and the primarypump 130; a torque regulation mechanism 150 that includes a rotor and astator; an energy storage device 160 that includes an energy dissipationmechanism 161; one or more sensors 170; and a controller 180. Variantsof the system or components thereof can be similar to the system and/orcomponents described in U.S. application Ser. No. 15/280,737, filed 29Sep. 2016, incorporated herein in its entirety by this reference.

3.1 Housing

The housing 110 functions to couple system components to a rotatingsurface 900 (e.g., the hub of a wheel of a vehicle). The housing 110 canalso function to mechanically protect (e.g., shield) system componentsfrom road debris and other objects that can transiently impact the wheelduring vehicle operation. The housing 110 can also function as amounting substrate for visual indicators of system performance (e.g.,for an LED that reports the system status). The housing 110 ispreferably removably coupled to a rotating surface 900, such as by wayof removable fasteners (e.g., nuts and bolts, screws, brackets, etc.);additionally or alternatively, the housing 110 can be permanentlycoupled to the rotating surface 900 (e.g., via welding, rivets,permanent fasteners, etc.). The housing 110 is preferably coupled to arotating surface 900 of the vehicle (e.g., that rotates during vehiclelocomotion), and is more preferably coupled to the hub of a vehiclewheel. However, the housing 110 can additionally or alternatively bestatically coupled to the rim of a vehicle wheel, a hubcap, to an axleof the vehicle, or any other suitable rotating or non-rotating surface900 of the vehicle. The housing 110 is preferably coupled to the vehicleby way of a set of fasteners (e.g., arranged to mate with an existingbolt pattern of the wheel hub), but can additionally or alternatively beintegrated directly into the vehicle (e.g., manufactured as part of thewheel hub or vehicle axel) or otherwise suitably attached to the vehicleby any other suitable mechanism. In a specific example, the housing 110is contiguous with a hubcap of the wheel, and is fastened to the wheel(e.g., via a set of lugnuts) and functions both as a hubcap and thesystem housing 110. The housing 110 is preferably rotatably coupled tothe drive mechanism 120 (e.g., such that the eccentric mass 121 canrotate relative to the housing 110) and statically coupled to the pumpbody 132 of the primary pump 130 (e.g., such that the primary pump 130rotates with the housing 110 as the wheel rotates. Alternatively, thehousing 110 can be statically coupled to the drive mechanism 120 androtatably coupled to the primary pump 130, or have any other suitablecoupling to the other system components. The housing 110 is preferablysubstantially rigid, but can additionally or alternatively be flexible,resilient, or have any other suitable structural characteristics. Thehousing 110 is preferably substantially impermeable to fluids (e.g.,waterproof) and can preferably at least partially shield systemcomponents from exposure to external liquids (e.g., water splashed ontothe wheel from the road surface), but can additionally or alternativelybe permeable.

In a first specific example, as shown in FIG. 6, the housing 110includes an inner housing that includes a first portion 111 (e.g.,mounting plate) that defines a hole pattern 1110 arranged to mate withan existing bolt pattern of the wheel, and a second portion 112 thatmates with the first portion 111 to cooperatively define a housing lumen113. The housing lumen 113 contains the primary pump 130, and defines anorifice 114 through which the pump can be connected to a first reservoir910 of fluid (e.g., ambient air) and a second reservoir of fluid (e.g.,the interior of a tire). The housing lumen 113 further contains thetorque regulation mechanism 150, which is disposed adjacent to a portionof the drive mechanism 120 such that a torque can be applied by thetorque regulation mechanism 150 to the drive mechanism 120 and therebyadjust the angular position of the eccentric mass 121 of the drivemechanism 120 (e.g., to transition the system into the pumping mode orfreewheeling mode). In this first specific example, the housing 110further contains the cam 122, and the eccentric mass 121 is arrangedexternal to the inner housing and coupled to the cam 122 by an axle thatextends through the second portion 112. The eccentric mass 121 in thisexample extends radially past a furthest radial extent of the innerhousing, and defines a portion along an arcuate section of therotational path of the eccentric mass 121 that extends axially towardthe first portion 111 of the inner housing. The housing 110 in thisexample can further include an outer housing that encloses the eccentricmass and the inner housing.

In a second specific example, the housing 11 is integrated directly witha hubcap of a vehicle wheel, and defines a housing lumen 113. Thehousing lumen 113 contains the primary pump 130, the drive mechanism120, the torque regulation mechanism 150, and the drive coupler 140, andis substantially sealed against the external environment. The housing nodefines an inlet, which can include a shielded cover (e.g., to preventforeign matter besides air from entrance), through which the primarypump 130 draws ambient air for compression and pumping during systemoperation. In this second specific example, the eccentric mass 121 isarranged internal to the housing 110. The eccentric mass 121 in thisexample extends radially toward an inner surface of the housing lumen113, and defines a portion along an arcuate section of the rotationalpath of the eccentric mass 121.

3.2 Drive Mechanism

The drive mechanism 120 of the tire inflation system 100 functions togenerate a pumping force to drive the primary pump 130. The drivemechanism 120 can also function to control the magnitude of the pumpingforce. The drive mechanism 120 preferably includes an eccentric mass 121and a cam 122, but can include any other suitable components forgenerating the pumping force (e.g., a rotary pump, a diaphragm pump, aturbopump, etc.). The pumping force generated by the drive mechanism 120is preferably applied in a radial direction relative to the rotationalaxis 123 of the drive mechanism 120 (e.g., the rotational axis 123 ofthe wheel), but can alternatively be applied in any suitable direction.The pumping force is preferably applied cyclically (e.g., in areciprocal manner to drive a reciprocating pump), but can additionallyor alternatively be a constant force, a steadily increasing ordecreasing force, or have any other suitable temporal profile.

The drive mechanism 120 can be rotatably coupled to the housing 110,such that the drive mechanism 120 is substantially stationary in atranslating reference frame (e.g., translating with the vehicle) as thehousing no and wheel rotate. The drive mechanism 120 preferably definesa rotational axis 123 about which a portion of the drive mechanism 120can rotate, and more preferably the cam 122 of the drive mechanism 120rotates about the rotational axis 123. However, the rotational axis 123can additionally or alternatively include the rotational axis 123 aboutwhich the eccentric mass 121 rotates, and/or any other suitable axis.The rotational axis 123 of the drive mechanism 120 is preferably coaxialwith a rotational axis 123 of the tire inflation system 100 as a whole(e.g., the wheel rotational axis 123), but can alternatively be offset(e.g., radially offset). The drive mechanism 120 preferably defines asingle rotational axis 123 (e.g., about which the cam 122 and eccentricmass 121 rotate), but can alternatively define multiple rotational axes(e.g., a first rotational axis 123 about which the eccentric mass 121rotates, and a second rotational axis 123 distinct from the firstrotational axis 123 about which the cam 122 rotates).

The cam 122 of the drive mechanism 120 functions to mechanically controlthe magnitude of the pumping force. The cam 122 can also function toconvert a torque received from the drive mechanism 120 to a linearforce, and apply the linear force against the reciprocating element 131of the primary pump 130 during the compression stroke. The torquereceived and/or the linear force applied can be, in variations, constantin time, variable in time, adjustable, or have any other suitablecharacteristics. In a first variation, the torque provided is modulatedin response to a back torque from the reciprocating pump (e.g., assistedby the torque regulation mechanism 150, defined by a feature of the cam122, etc.). The cam 122 preferably defines a bearing surface 1220, whichcan be an interior surface of the cam 122, an exterior surface of thecam 122, or any suitable combination of interior and exterior surfaces.The bearing surface 1220 can be continuous or discontinuous. In aspecific example, as shown in FIG. 5, the bearing surface 1220 isdefined within an interior of the cam 122 and includes a slotted lumen1221. However, the system can include any suitable cam 122 with anysuitable configuration.

The bearing surface 1220 can include a profile that, in variations,defines an arcuate surface, a surface having a non-uniform curvature, auniform curvature, and/or any other suitable spatial profile. Theprofile of the bearing surface 1220 preferably controls the magnitude ofthe pumping force throughout the compression stroke (e.g., a modulatedpumping force, a constant pumping force, etc.). The bearing surface 1220is preferably arcuate, and preferably has a non-uniform curvature (e.g.,an oblong profile or a reniform profile). Alternatively, the bearingsurface 1220 can have a uniform curvature (e.g., a circular profile), anangular profile, or any other suitable profile. The bearing surface 1220preferably includes a compression portion and a recovery portion,corresponding to the compression stroke and the recovery stroke of theprimary pump 130, respectively. The compression portion is preferablycontinuous with the recovery section, but can alternatively bediscontinuous. The bearing surface 1220 preferably has a first sectionhaving a high curvature (preferably positive curvature or convex butalternatively negative curvature or concave) adjacent a second sectionhaving low curvature (e.g., substantially flat or having negativecurvature compared to the first section). The bearing surface 1220preferably additionally includes a third section connecting the firstand second sections, wherein the third section preferably provides asubstantially smooth transition between the first and second sections byhaving a low curvature adjacent the first section and a high curvatureadjacent the second section. The compression portion preferably beginsat the end of the second section distal the first section, extends alongthe third section, and ends at the apex of the first section. Thecompression portion is preferably convex (e.g., when the bearing surface1220 is an external bearing surface 1220), but can alternatively beconcave. The apex of the first section preferably corresponds to the topof the compression stroke (compressed position). The recovery portionpreferably begins at the apex of the first section, extends along thesecond section, and ends at the end of the second section distal thefirst section. The recovery portion is preferably substantially flat orconcave (e.g., when the bearing surface 1220 is an external bearingsurface 1220), but can alternatively be convex. The end of the secondsection preferably corresponds to the bottom of the recovery stroke(recovered position). The slope of the compression portion is preferablyless than 30 degrees, but can alternatively have any suitable angle.When a roller is used as the force translator, the curvature of thebearing surface 1220 is preferably at least three times larger than theroller curvature or roller diameter, but can alternatively be larger orsmaller. However, the bearing surface 1220 can have any suitableprofile. The cam 122 is preferably substantially planar with the bearingsurface 1220 defined along the side of the cam 122, in a plane normal tothe rotational axis 123 of the cam 122 (e.g., normal the broad face ofthe cam 122). The bearing surface 1220 is preferably defined along theentirety of the cam 122 side, but can alternatively be defined along aportion of the cam 122 side. The generated pump force is preferablydirected radially outward of the rotational axis 123, more preferablyalong a plane normal to the rotational axis 123. Alternatively, the cam122 can have a rounded or otherwise profiled edge segment (transitionbetween the cam 122 broad face and the cam 122 side), wherein thebearing surface 1220 can include the profiled edge. Alternatively, thearcuate surface is defined by a face of the cam 122 parallel to therotational axis 123 of the cam 122, wherein the generated pump force canbe directed at any suitable angle relative to the rotational axis 123,varying from parallel to the rotational axis 123 to normal to therotational axis 123. The compression portion preferably encompasses themajority of the cam 122 profile, but can alternatively encompass halfthe cam 122 profile or a small portion of the cam 122 profile. In onevariation, the compression portion covers 315 degrees of the cam 122profile, while the recovery portion covers 45 degrees of the cam 122profile. However, the compression and recovery portions can cover anyother suitable proportion of the cam 122 profile.

The eccentric mass 121 (e.g., pendulum, offset mass) of the drivemechanism 120 functions to offset the center of mass of the drivemechanism 120 from the rotational axis 123 of the drive mechanism 120.The offset functions to retain an angular position of the drivemechanism 120 relative to a gravity vector, in order to generaterelative angular motion between the drive mechanism 120 and componentsstatically coupled to the rotating surface 900 (e.g., the housing 110,the pump body 132, etc.). The eccentric mass 121 is preferably ahomogenous (e.g., continuous) mass, but can additionally oralternatively be a heterogeneous (e.g., segmented, discontinuous, etc.)mass. In a specific example, as shown in FIG. 3B, the eccentric mass 121is rotatably attached to the housing 110 at the rotation axis of thewheel and is distributed along a portion of an arc centered at therotational axis 123. The eccentric mass 121 is preferably asubstantially singular, contiguous piece, but can alternatively be madeup of multiple pieces and/or segments. In the latter case, the multiplepieces and/or segments are preferably substantially similar in shape,angular and radial position, and mass, but can alternatively bedifferent in profile, mass, angular position, and/or radial position.The eccentric mass 121 can define a curved shape, flat surface, angularshape, and/or any other suitable geometry. At least a portion of theeccentric mass 121 preferably traces an arcuate section of the systemperimeter (e.g., aligned with the hub perimeter, inset from the hubperimeter, outside the housing 110 perimeter, inside the housing 110perimeter, etc.) such that a substantial fraction (e.g., between 10-90%,between 0-100%) of the mass is distributed along the arcuate section.The arcuate section can include any suitable are (e.g., 90°, 180°,etc.). However, in alternative variations, the eccentric mass 121 can bea spatially confined mass at an end of a pendulum that approximates apoint mass. In some variants, the azimuthal distribution of the mass canbe varied. For example, the eccentric mass 121 can include articulatedarms that can be unfolded outward (e.g., automatically unfolded,manually unfolded, etc.) to distribute the mass along an arcuate sectionin the azimuthal direction about the rotational axis 123. However, theeccentric mass 121 can be otherwise suitably configured and/or arranged.

The eccentric mass 121 is preferably curved, but can alternatively besubstantially flat, angled, or have other suitable shape. The radius ofthe eccentric mass 121 curvature is preferably maximized, such that theeccentric mass 121 traces an arcuate section of the pump systemperimeter. However, the eccentric mass 121 can have any other suitablecurvature. The eccentric mass 121 preferably extends at least 90 degreesabout the rotational axis 123 of the drive mechanism 120, morepreferably 180 degrees about the rotational axis 123, but can extendmore or less than 180 degrees about the rotational axis 123. Theeccentric mass 121 preferably has substantially more mass than the cam122, but can alternatively have a substantially similar mass or asmaller mass. The eccentric mass 121 preferably imparts 2 in-lb (0.225Nm) of torque on the cam 122, but can alternatively impart more or lesstorque.

The eccentric mass 121 is preferably a separate piece from the cam 122,and is preferably coupled to the cam 122 by a mass coupler 124.Alternatively, the eccentric mass 121 can be incorporated into the cam122, wherein the eccentric mass 121 is incorporated along the perimeterof the cam 122, incorporated into a half of the cam 122, or incorporatedalong any other suitable portion of the cam 122. The eccentric mass 121can be statically coupled to the cam 122 or rotatably coupled to the cam122. In the variation wherein the eccentric mass 121 is staticallycoupled to the cam 122, the eccentric mass 121 can be coupled to the cam122 at the rotational axis 123 of the cam 122, at the rotational axis123 of the drive mechanism 120, offset from the rotational axis 123 ofthe cam 122, or at any other suitable portion of the cam 122. Theeccentric mass 121 can be permanently connected to the cam 122.Alternatively, the eccentric mass 121 can be transiently connected(removably coupled) to the cam 122, wherein the eccentric mass 121 canbe operable between a pumping mode wherein the eccentric mass 121 iscoupled to the cam 122 and a non-pumping mode wherein the eccentric mass121 is disconnected from the cam 122. The mass coupler 124 preferablyhas a high moment of inertia, but can alternatively have a low moment ofinertia. The mass coupler 124 is preferably a disk, but canalternatively be a lever arm, plate, axle, or any other suitableconnection. The mass coupler 124 preferably couples to the broad face ofthe cam 122, but can alternatively couple to the edge of the cam 122,along the exterior bearing surface 1220 of the cam 122, to the interiorbearing surface 1220 of the cam 122, to an axle extending from of thecam 122 (wherein the cam 122 can be statically fixed to or rotatablymounted to the axle), or to any other suitable portion of the cam 122.The mass coupler 124 can couple to the cam 122 by friction, by atransient coupling mechanism (e.g., complimentary electric or permanentmagnets located on the cam 122 and mass coupler 124, a piston, a pin andgroove mechanism, etc.), by bearings, or by any other suitable couplingmeans. When the mass coupler 124 couples to the cam 122 by a transientcoupling mechanism, the mass coupler 124 is preferably operable betweena coupled mode, wherein the mass coupler 124 connects the eccentric mass121 to the cam 122, and a decoupled mode, wherein the mass coupler 124disconnects the eccentric mass 121 from the cam 122. The mass coupler124 can additionally function as a shutoff mechanism, wherein the masscoupler 124 is switched from the coupled mode to the decoupled mode inresponse to the detection of a shutoff event (e.g., the reservoirpressure reaching a threshold pressure). In one variation, the masscoupler 124 is a disk located within the lumen defined by an interiorbearing surface 1220 of the cam 122, wherein the disk can rotaterelative to the interior bearing surface 1220 in the decoupled mode andis coupled to the interior bearing surface 1220 by a friction element inthe coupled mode (e.g., the mass coupler 124 acts as a clutch). Inanother variation, the mass coupler 124 is rotatably mounted on an axleextending from the cam 122 by bearings, wherein the mass coupler 124 canbe statically coupled to the cam 122 by one or more sets of magnets orpistons extending from the adjacent broad faces of the cam 122 and masscoupler 124.

3.3 Primary Pump

The primary pump 130 of the tire inflation system 100 functions topressurize fluid with the pumping force generated by the drive mechanism120. The primary pump 130 preferably includes a reciprocating element131 and a pump body 132, and can optionally include a return mechanism133 and one or more inlets 134. However, the primary pump 130 caninclude any other suitable components. In variations, the primary pump130 can function to pressurize the fluid by receiving a reciprocatinglinear force at the reciprocating element 131. The primary pump 130 ispreferably statically mounted to the housing 110, wherein the housing110 is statically coupled to a rotating surface 900 of the vehicle(e.g., the hub of a wheel). However, the primary pump 130 canadditionally or alternatively be statically coupled to a surface thatrotates relative to the rotating surface 900 (e.g., that is stationaryin an external translating reference frame), such that relative motionis generated between the reciprocating element 131 of the primary pump130 and the rotating surface 900. The primary pump 130 is preferablypositioned radially distal the rotational axis of the drive mechanism120, but can additionally or alternatively be positioned at leastpartially coaxially with the rotational axis of the drive mechanism 120or otherwise suitably arranged. The position of the primary pump 130relative to the drive mechanism 120 can be fixed or adjustable (e.g.,manually adjustable, automatically adjustable, etc.).

In a first variation, the primary pump 130 includes a positivedisplacement pump wherein the reciprocating element 131 is a piston, anddefines a pump cavity (e.g., pump lumen, cylinder) within the pump body132. In a specific example of this variation, the primary pump 130 is areciprocating piston pump. In a second variation, the primary pump 130includes a peristaltic pump. However, the primary pump 130 can includeany other suitable pumping mechanism.

The reciprocating element 131 of the primary pump 130 functions totranslate back and forth in a reciprocating manner within the pump body132 to compress fluid transferred from the first reservoir 910 to thesecond reservoir (e.g., to the tire). The reciprocating element 131 canalso function to receive the pumping force from the cam 122 andtranslate within the lumen of the pump, actuating relative to the pumpbody 132. This actuation preferably creates a variable pressure withinthe lumen. The reciprocating element 131 is preferably operable betweena compressed position and a recovered position. In the compressedposition, a portion of the reciprocating element 131 (e.g., the center)is preferably proximal the pump body 132 bottom. In the recoveredposition, the portion of the reciprocating element 131 is preferablydistal the pump body 132 bottom, and is preferably proximal the pumpbody 132 opening. The reciprocating element 131 preferably travels alonga compression stroke to transition from the recovered position to thecompressed position, and travels along a recovery stroke to transitionfrom the compressed position to the recovered position. Thereciprocating element 131 can additionally be positioned at apressurized position, wherein the reciprocating element 131 is locatedat a second position distal the pump body 132 bottom, wherein the secondposition is further from the pump body 132 bottom than the recoveredposition. The reciprocating element 131 is preferably at the pressurizedposition when the force provided by the lumen pressure exceeds the forceprovided by the cam 122 on the reciprocating element 131.

The reciprocating element 131 preferably translates along an actuationaxis within the primary pump 130 throughout the compression stroke, andcan additionally translate along the actuation axis throughout therecovery stroke. The reciprocating element 131 preferably includes anactuating area that provides the pressurization force. The actuatingarea is preferably the surface area of a broad face of the reciprocatingelement 131, more preferably the surface area of the broad face proximalthe lumen but alternatively any other suitable broad face.Alternatively, the actuating area can be the surface area of a sectionof the reciprocating element 131 that translates between the compressedposition and the recovered position (e.g., the center portion).

The reciprocating element 131 preferably forms a fluid impermeable sealwith the pump body 132, more preferably with the walls defining the pumpbody 132 opening, such that the reciprocating element 131 substantiallyseals the pump body 132 opening. The reciprocating element 131 can besealed to the pump body 132 by a retention mechanism. The retentionmechanism is preferably a clamp that applies a compressive force againstthe reciprocating element 131 edge and the pump body 132 wall, but canalternatively be screws or bolts through the reciprocating element 131edge, adhesive between the reciprocating element 131 and the pump body132 wall or over the reciprocating element 131 and the pump body 132wall, or any other suitable retention mechanism. The reciprocatingelement 131 can also be sealed against the pump body 132 wall by meltingthe interface between the reciprocating element 131 and pump body 132wall, or by any other suitable means of sealing the reciprocatingelement 131 against the pump body 132 wall.

The reciprocating element 131 is preferably a flexible diaphragm, butcan alternatively be a substantially rigid piston, a piston coupled tothe diaphragm, or any other suitable element that actuates in responseto the pumping force. The diaphragm is preferably a rolling diaphragm(e.g., with a rolled perimeter, wherein the diaphragm is preferablycoupled to the pump body 132 with the extra material distal the lumen)but can also be a flat diaphragm, a domed diaphragm (preferably coupledto the pump body 132 with the apex distal the lumen, but alternativelycoupled to the pump body 132 with the apex proximal the lumen), or anyother suitable diaphragm.

The pump body 132 functions to cooperatively compress fluid along withthe reciprocating element 131. The pump body 132 defines a lumen (e.g.,cylinder cavity) in which the fluid is compressed. The pump body 132 ispreferably statically mounted to the housing no, but can be otherwisesuitable arranged relative to the housing 110 and/or other systemcomponents.

The primary pump 130 can include a return mechanism 133, which functionsto bias the reciprocating element 131 in the reverse direction to thedirection of the compression stroke during the recovery stroke. Thereturn mechanism 133 preferably provides a recovery force that is lessthan the compression force provided by the third section of the cam 122,but larger than the force applied by the cam 122 in the second section.The recovery force is preferably provided in a direction substantiallyparallel to a radial vector extending from the rotational axis of thedrive mechanism 120, but can alternatively be provided in any suitabledirection. The return mechanism 133 is preferably located on the pumpbody 132 side of the reciprocating element 131 (distal the cam 122across the reciprocating element 131), wherein the return mechanism 133preferably pushes the reciprocating element 131 from the compressedposition, through the recovery stroke, and to the recovered position.Alternatively, the return mechanism 133 can be located on the cam 122side of the reciprocating element 131 (distal the pump body 132 acrossthe reciprocating element 131), wherein the return mechanism 133 pullsthe reciprocating element 131 back to the recovered position from thecompressed position. The return mechanism 133 is preferably coupled tothe perimeter of the reciprocating element 131 or to a component (e.g.,a brace) coupled to the reciprocating element 131 and extending past thepump body 132 walls, but can alternatively be coupled to the body of thereciprocating element 131 (e.g., to the section actuating between thecompressed position 222 and the recovered position). The returnmechanism 133 is preferably coupled to the reciprocating element 131external the pump body 132, but can alternatively be coupled to thereciprocating element 131 within the pump body 132 240. The returnmechanism 133 is preferably a spring, but can also include the intrinsicproperties of the actuation element (e.g., the elasticity of thediaphragm) or any other suitable return mechanism 133.

The return mechanism 133 can, in further variations, include an internalspring, an exterior spring (e.g., mounted to an outer surface of thepump body 132), a secondary cam 122 that drives the reciprocatingelement 131 in opposition to the cam 122 of the drive mechanism 120,and/or any other suitable mechanism.

The primary pump 130 can include one or more inlets 134, which functionto receive fluid from the first reservoir 910 into the lumen of the pumpbody 132 for compression. The inlets 134 can be perpetually open (e.g.,fixed orifice 114 s in the pump body 132), actuatable (e.g., viacontrollable valves), shielded (e.g., to protect against influx offoreign matter besides the working fluid), or otherwise suitablyconstituted.

3.4 Drive Coupler

The drive coupler 140 of the tire inflation system 100 functions toactuate the reciprocating element 131 of the primary pump 130 throughthe compression stroke as the primary pump 130 rotates about therotational axis of the wheel. The drive coupler 140 can also function totranslate the reciprocating element 131 through the recovery stroke. Thedrive coupler 140 is preferably coupled between the cam 122 of the drivemechanism 120 and the reciprocating element 131 of the primary pump 130,but can alternatively be otherwise suitably coupled. In a firstvariation, the drive coupler 140 is coupled to the cam 122 by way of aroller bearing 141 captive within an oblong slot defined by the cam 122,and pinned to the reciprocating element 131 (e.g., rotatable about afixed point). In a second variation, the drive coupler 140 is pinned toboth the cam 122 and the reciprocating element 131. The drive coupler140 preferably defines an axis having an arcuate position that is fixedrelative to the arcuate position the primary pump 130 (e.g., the angularposition of the drive coupler 140 about the rotational axis of the wheelis fixed relative to the angular position of the primary pump 130).Preferably, the drive coupler 140 rotates with the primary pump 130 asboth components rotate about the rotational axis of the wheel. However,the drive coupler 140 can additionally or alternatively exhibit adifferent relative rotation to the primary pump 130 (e.g., a differentangular velocity, a different trajectory, an off-axis trajectory, etc.).

3.5 Torque Regulation Mechanism

The torque regulation mechanism 150 functions to regulate the torquesupplied to the drive mechanism 120 in order to transition the tireinflation system 100 between the pumping and freewheeling operationmodes. The torque regulation mechanism 150 can also function to receivetorque from the drive mechanism 120 and convert the received torque intoelectrical potential energy (e.g., to operate as a dynamo). The torqueregulation mechanism 150 can also function to provide a torque (e.g.,based on instructions from the controller 180) to transition the tireinflation system 100 between the pumping mode and the freewheeling mode,and/or to maintain the tire inflation system 100 in one or more of thepumping mode, the freewheeling mode, and any other suitable operatingmodes. The torque regulation mechanism is preferably configured to applya torque based on instructions received from a controller. Theinstructions can be automatically generated by the controller, generatedby a system user in communication with the controller (e.g., manuallyvia an electromechanical interface, wirelessly via a wirelesstransceiver, etc.), or otherwise suitably generated.

The torque regulation mechanism 150 preferably includes a first portion151 and second portion 152 that rotate relative to one another, but canbe otherwise configured. In one variation, the first portion 151includes a stator that is statically coupled to a rotating surface 900(e.g., the housing 110 statically coupled to the wheel) and the secondportion 152 includes a rotor that is statically coupled to the eccentricmass 121 such that the rotor rotates along with the eccentric mass 121.In another variation, the stator is statically coupled to the eccentricmass 121 and the rotor is coupled to the rotating surface 900 by way ofthe housing 110. The rotor and stator are preferably concentricallyarranged, but can alternatively be offset (e.g., and mechanically linkedby a force transfer mechanism 153). However, the first and secondportion 152S of the torque regulation mechanism 150 s can be otherwisesuitably relatively arranged. In a specific example, the torqueregulation mechanism 150 is coupled to the eccentric mass 121 via anintermediate force transfer mechanism 153 (e.g., a gear, a gearbox, abelt, a chain, a clutch, etc.). The torque regulation mechanism 150 ispreferably electrically coupled to the controller 180 (e.g., to receivecontrol instructions and/or signals) and the energy storage device 160by way of one or more direct electrical power and/or data connections.However, the torque regulation mechanism 150 can be otherwise suitablycoupled to the controller 180 and/or energy storage device 160.

The torque regulation mechanism 150 is preferably arranged at adifferent plane from the rotation plane of the eccentric mass 121 (e.g.,distal the rotation plane of the eccentric mass 121 in a direction awayfrom the wheel hub, distal the rotation plane of the eccentric mass 121in a direction toward the wheel hub, etc.). As shown in FIG. 4A, thetorque regulation mechanism 150 can be arranged toward the vehicle(e.g., toward the vehicle centerline) relative to the drive mechanism120 (e.g., the eccentric mass 121 of the drive mechanism 120). As shownin FIG. 4B, the torque regulation mechanism 150 can be arranged awayfrom the vehicle relative to the drive mechanism 120. However, thetorque regulation mechanism 150 can additionally or alternatively bearranged in the same plane (e.g., coaxially arranged, offset from therotation axis of the eccentric mass 121, etc.). In a first variation, asshown in FIG. 3A, the torque regulation mechanism 150 is arrangedcoaxially with the rotation axis of the wheel and the eccentric mass121. In further variations, as shown in FIGS. 3B and 3C, the torqueregulation mechanism 150 is arranged at an offset position from therotation axis of the eccentric mass 121, and connected to the eccentricmass 121 via a force transfer mechanism 153 (e.g., a chain and sprocket,a drive belt, etc.). However, the torque regulation mechanism 150 can beotherwise arranged relative to the drive mechanism 120, axis ofrotation, or eccentric mass 121. The torque regulation mechanism 153 canapply a: radially inward force, radially outward force, linearly outwardforce (e.g., away from the wheel or longitudinal vehicle axis), linearlyinward force (e.g., toward the vehicle), arcuate force (e.g., within thesame plane as eccentric mass rotation), or any other suitable force tothe eccentric mass, cam, pump, or other pumping component. The torqueregulation mechanism can be statically mounted to: the housing (e.g.,interior, exterior, component proximal the tire, component distal thetire, an arcuate segment of the sidewall, etc.), the eccentric mass, thecam, the pump, or to any suitable system component.

The torque regulation mechanism 150 preferably includes an electricmotor, but can additionally or alternatively include any suitable torquegeneration and/or regulation mechanism. The electric motor can be anoutrunner motor, an inrunner motor, a brushed motor, a brushless motor,an alternating-current motor, a directocurrent motor, a permanent magnetmotor, an induction motor, a servo motor, a stepper motor, and/or anyother suitable motor. The electric motor preferably generates arotational force, but can alternatively generate a linear force (e.g.,be a linear actuator) or generate any suitable force. In variations, thetorque regulation mechanism 150 can include mechanical torque regulationcomponents, such as gears, springs, levers, and any other suitableclockwork components that do not require electrical energy foroperation.

The rotor of the torque regulation mechanism 150 functions to moverelative to the stator under an applied electromotive force to generatea torque on components statically coupled to the rotor. The rotor canalso function to move relative to the stator under an applied torque togenerate an electromotive force that can be harvested and stored aselectrical potential energy (e.g., at the energy storage device 160). Ina first variation, the rotor is statically coupled to a surface thatrotates with the wheel. In a second variation, the rotor is staticallycoupled to a surface that is substantially stationary relative to thewheel. However, the rotor can be otherwise suitably coupled.

The stator of the torque regulation mechanism 150 functions to moverelative to the rotor under an applied electromotive force to generate atorque on components statically coupled to the stator. The stator canalso function to move relative to the rotor under an applied torque togenerate an electromotive force that can be harvested and stored aselectrical potential energy (e.g., at the energy storage device 160). Ina first variation, the stator is statically coupled to a surface that issubstantially stationary relative to the wheel. In a second variation,the stator is statically coupled to a surface that rotates with thewheel. However, the stator can be otherwise suitably coupled.

The torque regulation mechanism 150 can include an engagement mechanism154 that functions to mechanically engage and/or disengage the eccentricmass 121 from other system components. For example, the engagementmechanism 154 can include a clutch that mechanically engages theeccentric mass 121 and the drive coupler 140 during system operation inthe pumping mode (e.g., such that a drive force is provided by theeccentric mass 121 when the eccentric mass 121 is maintained at anon-zero hanging angle), and that mechanically disengages the eccentricmass 121 and the drive coupler 140 during system operation in thefreewheeling mode (e.g., such that no drive force is provided by theeccentric mass 121 irrespective of the angular position and/or velocityof the eccentric mass 121). In some variations, the mass coupler 124 canfunction as an engagement mechanism 154. However, the engagementmechanism 154 can include any other suitable mechanism for mechanicallyretaining the eccentric mass 121 relative to the pump and/or otherrotating components of the system.

In a first specific example, as shown in FIG. 6, the torque regulationmechanism 150 includes an electric motor wherein the stator of theelectric motor is rigidly attached to the eccentric mass 121 (e.g., anarcuate segment of the stator defines a portion of the eccentric mass121), the rotor of the electric motor is rigidly coupled to a rotatingsurface 900 (e.g., the housing 110, the wheel hub, via mountingcomponents, directly coupled via a weld, etc.), and the rotor isconnected to the drive coupler 140 that drives the primary pump 130. Ina second specific example, the torque regulation mechanism 150 includesan electric motor wherein the stator is rigidly mounted to the housing110, and is offset from the tire inflation system 100's rotational axisand is connected to the eccentric mass 121 by a force linkage (e.g., agearbox).

3.6 Energy Storage Device

The tire inflation system 100 can include an energy storage device 160,which functions to provide power to the torque regulation mechanism 150.The energy storage device 160 can also function to receive power fromthe torque regulation mechanism 150 (e.g., when the torque regulationmechanism 150 is operating as a dynamo). The energy storage device 160can, in some variations, function to store compressed fluid generated bythe primary pump 130 (e.g., in a compressed air canister). The energystorage device 160 is preferably coupled to the torque regulationmechanism 150 (e.g., via a direct electrical connection for powerprovision and/or reception), but can additionally or alternatively becoupled to the controller 180, primary pump 130, and/or any other systemcomponents. The system preferably includes a single energy storagedevice 160, but can additionally or alternatively include redundant(e.g., multiple) energy storage device 160 s (e.g., to provide backuppower to system components such as the torque regulation mechanism 150).The energy storage device 160 is preferably coupled to the housing 110and rotates with the wheel, but can alternatively be coupled to theeccentric mass 121 or to any other suitable system component. The energystorage device 160 is preferably arranged axially inward (e.g., alongthe direction of the vehicle axle) from the eccentric mass 121, but canalternatively be arranged axially outward from the eccentric mass 121.In a first variation, the energy storage device 160 includes a battery.In further variations, the energy storage device 160 can include a supercapacitor, a compressed air canister, one or more springs, and/or anyother suitable energy storage mechanisms.

The energy storage device 160 can optionally include an energydissipation mechanism 161 that functions to dissipate excess energygenerated by the torque regulation mechanism 150 (e.g., when the torqueregulation mechanism 150 is operating as a dynamo) in cases wherein theenergy storage device 160 is at full capacity (e.g., when the battery isfully charged). For example, the energy dissipation mechanism 161 caninclude an electrical resistor, a resistor network, and/or any othersuitable passive component for dissipating electrical energy invariations wherein the energy storage device 160 includes an electricalenergy storage device 160 (e.g., a battery, capacitor, supercapacitor,etc.). In another example, the energy dissipation mechanism 161 caninclude an active energy dissipation mechanism 161, such as a fan, waterpump, light emitting element, and/or any other suitable poweredmechanism, to utilize excess recovered energy stored at the energystorage device 160 (e.g., for the purpose of cooling, user notificationgeneration, etc.).

3.7 Sensors

The tire inflation system 100 can include one or more sensors 170, whichfunction to sense operational parameters of the system (e.g., tirepressure, whether the system is in an “on” state or an “off” state,whether the system is operating within nominal ranges, etc.). Thesensors 170 can also function to provide sensor data to a controller180. The sensors 170 can also function to detect, in cooperation withthe controller 180, whether the system is operating in the freewheelingand/or pumping modes (e.g., by comparing a measured rotational velocityof the eccentric mass 121 with a measured rotational velocity of thewheel). The system can include one or more pressure sensors 170, whichcan be connected to the output of the primary pump 130 to monitor thepressure of the fluid provided to the tire. The sensor(s) are preferablyconnected to the controller 180 (e.g., via a signal pathway) to providesensor data (e.g., sensor signals) to the controller 180, and mounted onand/or within the housing 110 (e.g., for mechanical support). However,the sensor(s) can be otherwise suitably connected. System sensors 170can include pressure sensors 170 (e.g., capacitively-based diaphragmdeflection gauges), flow rate sensors 170, mass flow sensors 170 (e.g.,inline impellers), orientation sensors 170 (e.g., accelerometers,inertial measurement units, gyroscopes, etc.), rotary encoders, and/orany other suitable type of sensor.

In a first variation, the system includes a pressure sensor arranged atan interface between the output of the primary pump 130 and the inlet ofthe second reservoir (e.g., the tire) to continuously measure the staticpressure of the second reservoir. In a second specific example, thesystem includes a rotary encoder coupled to the torque regulationmechanism 150 that periodically measures (e.g., at 1 kHz) the angularposition of the rotor of the torque regulation mechanism 150.

In a second variation, the system includes a sensor (e.g., an angularposition sensor, angular velocity sensor, etc.) communicatively coupledto the controller 180, that detects and outputs the relative angularvelocity between the eccentric mass 121 and the primary pump 130,wherein the controller 180 generates instructions based on an output ofthe differential angular velocity sensor and controls the torqueregulation mechanism 150 based on the instructions. The sensor can bearranged to be in contact with the eccentric mass 121 (e.g., a contactsensor) and output the angular position and/or velocity based acharacteristic of the contact; for example, the electrical resistancethrough a portion of the sensor can increase or decrease based on theposition at which the sensor contacts the eccentric mass 121. The sensorcan additionally or alternatively be physically separated from theeccentric mass 121; for example, the sensor can include an opticalsensor that counts the frequency of optical occlusions of the opticalsensor by the eccentric mass 121 during rotation of the eccentric mass121 and/or the wheel, from which the angular velocity of the eccentricmass 121 can be computed (e.g., by the controller 180). However, thesystem can include any other suitable sensors 170.

3.8 Controller

The tire inflation system 100 can include a controller 180, whichfunctions to generate control in puts in response to received sensordata and/or instructions. The controller 180 can also function tocontrol the torque regulation mechanism 150 to operate the systembetween operating modes (e.g., the pumping mode, the freewheeling mode,etc.). The controller 180 can also function to adjust the pressure setpoint of the tire inflation system 100 and to control the tire inflationsystem 100 to maintain the tire pressure at the pressure set point. Thecontroller 180 can also function to generate messages in response tosystem behavior (e.g., error codes). The controller 180 can becommunicatively coupled to the sensors 170 and torque regulationmechanism 150 of the system, and in some variations can becommunicatively coupled to a remote computing system (e.g., a vehicleECU, a mobile device within the vehicle, etc.) via a communicationsystem (e.g., wired communications system; wireless communicationssystem, such as Bluetooth, WiFi, Zigbee, cellular, etc.).

In a first specific example of controller 180 operation, the controller180 detects a perturbative torque to the eccentric mass 121 (e.g., froman angular position sensor of the eccentric mass 121) and controls thetorque regulation mechanism 150 (e.g., an electric motor) to dampen theperturbative torque and maintain the system in the pumping mode (e.g.,maintain a non-zero angle between a gravity vector and the eccentricmass 121) and prevent the perturbative torque from transitioning thesystem from the pumping mode into the freewheeling mode. Theperturbative torque can be detected via heuristic comparisons (e.g.,pattern matching), deterministic comparisons (e.g., an oscillationexceeding a threshold perturbation magnitude), and/or in any othersuitable manner. The perturbative torque can be a back torque generatedby the primary pump 130 (e.g., due to reciprocating pump dynamics), adisturbance originating from road roughness, external forces and/orshocks, or any other source of torque or force.

In a second specific example of controller 180 operation, the controller180 receives an instruction (e.g., from a vehicle control system, auser, etc.) to cease pumping (e.g., to transition the system into thefreewheeling operating mode from the pumping mode), and in responsecontrols the torque regulation mechanism 150 to apply a torque to theeccentric mass 121 to induce rotation of the eccentric mass 121 atsubstantially the same angular velocity of the rotating wheel.

3.9 System Examples

In a first specific example of the tire inflation system 100, the systemincludes a drive mechanism 120, a pump, a drive coupler 140, a torqueregulation mechanism 150, and a controller 180. The drive mechanism 120defines a rotational axis, and includes a cam 122 rotatable about therotational axis and an eccentric mass 121 coupled thereto that offsets acenter of mass of the drive mechanism 120 from the rotational axis alongthe radial vector. The pump is arranged radially distal the rotationalaxis of the drive mechanism 120, and includes a chamber defining achamber lumen, and a reciprocating element 131 arranged at leastpartially within the chamber lumen and translateable along a pump axisnormal to the rotational axis. The drive coupler 140 is coupled betweenthe cam 122 at a first position and the reciprocating element 131 at asecond position. The first position is radially distal the rotationalaxis about which the cam 122 rotates, and the second position is fixed(e.g., pinned) to the reciprocating element 131. The torque regulationmechanism 150 (e.g., an electric motor, a clockwork mechanism, etc.)includes a first portion rigidly coupled to the eccentric mass 121, anda second portion rotatably coupled to the first portion. The controller180 is communicatively coupled to the torque regulation mechanism 150(e.g., by a hardwire data connection, serial data port, etc.), and to asensor (e.g., an angular velocity sensor, an angular position sensor, arotary encoder, etc.) that senses an angular characteristic (e.g.,angular position, angular velocity, etc.) of the eccentric mass 121relative to a gravity vector. The controller 180 is configured tooperate the system between the pumping mode and the freewheeling mode.In the pumping mode, the torque regulation mechanism 150 maintains theeccentric mass 121 at a hanging angle (e.g., defined by the radialvector between the rotational axis and an end of the eccentric mass 121opposing the point at which the eccentric mass 121 is connected to therotational axis) greater than 0° relative to the gravity vector. Incases where the system is in the freewheeling mode prior totransitioning to the pumping mode, the torque regulation mechanism 150applies a torque to the eccentric mass 121 to stimulate the eccentricmass 121 to exit a spin condition (e.g., wherein the eccentric mass 121is rotating about the rotational axis at substantially the same angularvelocity as the wheel to which the system is attached).

In a related specific example, the system further includes an energystorage device 160 (e.g., a battery, a torsional spring, a pneumaticcylinder, etc.) communicatively coupled (e.g., via a direct electricalconnection, a direct mechanical connection, a fluid connection, etc.) tothe torque regulation mechanism 150 and the controller 180. The energystorage device 160 is operably between a harvesting mode and a poweringmode. In the harvesting mode, the energy storage device 160 receives andstores energy harvested from the torque regulation mechanism 150, whichin turn receives a torque input from the eccentric mass 121. Forexample, in a case where the eccentric mass 121 is decoupled from thecam 122 and/or primary pump 130 (e.g., such that zero drive force isprovided to the reciprocating element 131), the eccentric mass 121 canbe maintained at a non-zero hanging angle relative to a gravity vectorin order to harvest energy (e.g., gravitational energy) to store withinthe energy storage device 160. In the powering mode, the energy storagedevice 160 provides energy to the torque regulation mechanism 150, whichin turn provides a torque input to the eccentric mass 121. The systemand the energy storage device 160 of this example is preferably operatedbetween the harvesting and powering mode by way of the controller 180,but can be additionally or alternatively operated by any suitablemechanism or control instructions.

The systems and methods of the preferred embodiment and variationsthereof can be embodied and/or implemented at least in part as a machineconfigured to receive a computer-readable medium storingcomputer-readable instructions. The instructions are preferably executedby computer-executable components preferably integrated with the systemand one or more portions of the processor and/or the controller 180 430.The computer-readable medium can be stored on any suitablecomputer-readable media such as RAMs, ROMs, flash memory, EEPROMs,optical devices (CD or DVD), hard drives, floppy drives, or any suitabledevice. The computer-executable component is preferably a general orapplication specific processor, but any suitable dedicated hardware orhardware/firmware combination device can alternatively or additionallyexecute the instructions.

In a second specific example, the tire inflation system 100 includes adrive mechanism 120, a drive coupler 140, a reciprocating pump, a torqueregulation mechanism 150, a housing no, and a controller 180. The drivemechanism 120 defines a rotational axis, and includes a cam 122rotatable about the rotational axis and an eccentric mass 121 coupled tothe cam 122 that offsets a center of mass of the drive mechanism 120from the rotational axis along a radial vector and is rotatable aboutthe rotational axis. The cam 122 includes a slotted lumen that definesan interior surface. The drive coupler 140 defines a first and secondend, and the first end of the drive coupler 140 is coupled to the cam122 at a position radially distal the rotational axis. The first endfurther includes a roller bearing, and at the coupling position to thecam 122 the roller bearing is captivated within the slotted lumen andcontacts the cam 122 at the interior surface. The second end is coupledto the reciprocating pump. The reciprocating pump is arranged radiallydistal the rotational axis of the drive mechanism 120, and includes apump body 132 (e.g., chamber) that defines a chamber lumen, and areciprocating element 131 arranged at least partially within the chamberlumen and translatable along a pump axis defined longitudinally alongthe chamber lumen and is normal to the rotational axis (i.e., the pumpaxis is perpendicular to the rotational axis of the system). Thereciprocating pump further includes a return mechanism 133 (e.g., aspring) that applies a return force (e.g., a spring force) that biasesthe reciprocating element 131 along the pump axis towards theuncompressed position (e.g., away from the base of the chamber lumen).The return mechanism 133 is fixed to the reciprocating element 131 andthe chamber, and is arranged externally to the chamber lumen (e.g., onthe outside of the pump body 132). The torque regulation mechanism 150applies a controllable torque to the eccentric mass 121, such that thecontrollable torque urges rotation of the eccentric mass 121 about therotational axis. The torque regulation mechanism 150 further includes anengagement mechanism 154 (e.g., a clutch) that engages the eccentricmass 121 in at least a first and second configuration. In the firstconfiguration, the eccentric mass 121 is mechanically coupled to theprimary pump 130 (e.g., via the cam 122 and the drive coupler 140),whereas in the second configuration, the eccentric mass 121 ismechanically decoupled from the primary pump 130 (e.g., via rotationaldecoupling from the cam 122, mechanical decoupling from the drivecoupler 140, etc.). The torque regulation mechanism 150 further includesan electric motor and a force transfer mechanism 153 (e.g., a gearbox),and the force transfer mechanism 153 is coupled between the electricmotor and the eccentric mass 121 such that torques transmitted betweenthe electric motor and the eccentric mass 121 are mechanicallytransferred through the gears of the gearbox. The electric motor isarranged at an offset position from the rotational axis, and therotational axis of the electric motor (e.g., defined by an output shaftof the motor) is parallel to the rotational axis of the eccentric mass121. The housing 110 retains the pump, the torque regulation mechanism150, and the cam 122. The eccentric mass 121 is arranged external to thehousing 110 and coupled to the cam 122 by a fixed axle that extendsthrough an orifice 114 of the housing 110 along the rotational axis. Aportion of the eccentric mass 121 is rotatable about the rotational axisalong a circular path, the circular path having a radius greater thanthe farthest radial extent of the housing 110 (e.g., outside theperimeter of the housing 110). The eccentric mass 121 is distributedalong an arcuate section of the circular path (e.g., a 90° section, a180° section, etc.).

In the second specific example above, the controller 180 iscommunicatively coupled to the torque regulation mechanism 150 (e.g.,via a direct electrical connection, a serial data connection, a paralleldata connection, a wireless data connection, etc.) and generatesinstructions which are provided (e.g., by the controller 180) to thetorque regulation mechanism 150 to operate the system between a firstand second mode. In the first mode, the drive coupler 140 ismechanically engaged with the eccentric mass 121, such that a driveforce is provided to the primary pump 130 by the relative motion betweenthe eccentric mass 121 and the primary pump 130. In the second mode, thedrive coupler 140 is mechanically disengaged from the eccentric mass121, such that no drive force is provided to the primary pump 130 by therelative motion (e.g., in cases where relative motion occurs) betweenthe eccentric mass 121 and the primary pump 130 or by any otherkinematic mechanism.

Although omitted for conciseness, the preferred embodiments includeevery combination and permutation of the various system componentsand/or method blocks.

The FIGURES illustrate the architecture, functionality and operation ofpossible implementations of systems, methods and computer programproducts according to preferred embodiments, example configurations, andvariations thereof. In this regard, each block in the flowchart or blockdiagrams may represent a module, segment, step, or portion of code,which comprises one or more executable instructions for implementing thespecified logical function(s). It should also be noted that, in somealternative implementations, the functions noted in the block can occurout of the order noted in the FIGURES. For example, two blocks shown insuccession may, in fact, be executed substantially concurrently, or theblocks may sometimes be executed in the reverse order, depending uponthe functionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts, or combinations of special purpose hardware andcomputer instructions.

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the preferred embodiments of the invention withoutdeparting from the scope of this invention defined in the followingclaims.

We claim:
 1. A system for tire inflation comprising: an eccentric masshaving a center of mass offset from a rotational axis; a pump mountableto a tire and coupled to the eccentric mass, wherein the pumpreciprocates in response to tire rotation relative to the eccentricmass; and a torque regulation mechanism configured to control operationof the eccentric mass between: a pumping mode, wherein the torqueregulation mechanism maintains the eccentric mass within a predeterminedangle relative to a gravity vector; and a non-pumping mode.